1. Field
This disclosure relates to a method of forming a polycrystalline silicon layer, a thin film transistor including the polycrystalline silicon layer, and an organic light emitting device.
2. Description of the Related Art
A thin film transistor is a switching and/or driving device, and includes an electrode and an active layer. The active layer mainly includes silicon, which may be classified as amorphous silicon or polycrystalline silicon depending on the crystal states.
Since the polycrystalline silicon has higher mobility compared to the amorphous silicon, a thin film transistor including polycrystalline silicon may provide a high response speed and low power consumption.
Methods of forming polycrystalline silicon may include solid-phase crystallization (SPC) and excimer laser crystallization (ELC). However, the solid-phase crystallization involves heat treatment at a high temperature for a long time thus causing deformation of a substrate, and the excimer laser crystallization requires expensive laser equipment and has difficulty in uniformly crystallizing a substrate on the whole.
To compensate the above crystallization methods, metal induced crystallization (MIC), metal induced lateral crystallization (MILC), super grain silicon crystallization (SGS), etc., which crystallize using a metal catalyst, have been suggested. However, according to the above crystallization methods, large quantities of metal catalysts may still remain in the polycrystalline silicon layer, and thus thin film transistor characteristics may be affected.